Modeling the response of optical and hydrophobic properties of codoped TiO2 thin films

Abstract

In the current research, the effect of Cd- and Sr-codoped TiO2 thin films on bandgap and the degree of wettability were studied using a statistical method. The selected parameters were two types of different dopants, including Sr and Cd, and the weight percent of each dopant in the range of 0 to 20%. The experiments were designed using the response surface methodology in order to model and analyze the effect of selected parameters on responses. The responses included bandgap energy and contact angle. Analysis of variance was used to validate adequacy of the proposed mathematical models. The obtained mathematical models were useful not only for predicting the bandgap and contact angle with higher accuracy but also for selecting optimum dopant parameters to achieve the desired bandgap and hydrophilic properties. By using the optimized conditions resulted from the models, minimum bandgap and contact angle were calculated 2.24 eV and 3.82°, respectively, where the optimum condition of selected parameters obtained 19 and 2.50 wt% for Cd and Sr, respectively.